Automated diagnostic analyzers having vertically arranged carousels and related methods

An apparatus comprising:

• a reagent carousel rotatably coupled to a base about a first axis of rotation;
• a reaction carousel rotatably coupled to the base about a second axis of rotation, the reaction carousel disposed above the reagent carousel;
• and
• a first pipette in fluid communication with the reagent carousel and the reaction carousel.

A method comprising:

• rotating a first carousel relative to a base, the first carousel having a first diameter, a first axis of rotation, an outer annular array of containers and an inner annular array of containers concentric with the outer annular array;
• rotating a second carousel relative to the base, the second carousel having a second diameter, a second axis of rotation and a plurality of vessels and being vertically spaced over the first carousel such that at least a portion of the second carousel is disposed over the first carousel;
• and
• aspirating a first fluid from the first carousel via a first pipetting mechanism offset from the second axis of rotation.